Recording method, recording apparatus, and recording medium

ABSTRACT

The present invention is a recording method for recording data to a disc shaped record medium  10  corresponding to a hierarchical file system, the method comprising the steps of recording management information for managing a hierarchical structure of the file system to a particular area  16  of the disc shaped record medium, treating an unused area of the particular area  16  as a particular file, and recording information with respect to an initial location and an initial length of the particular file and information with respect to a current location and a current length of the particular file to the particular area  16.

TECHNICAL FIELD

The present invention relates to a recording method for recording dataon a rewritable record medium, in particular, to a recording method thatallows hierarchical structure management information for a file systemand information that represents a record location of entity data of afile to be recovered when these information gets defective. In addition,the present invention relates to a recording method that allows a driveapparatus to recognize a file structure at high speed when data isadded. Moreover, the present invention relates to a recording apparatusthat uses the recording method and a record medium on which data hasbeen recorded corresponding to the recording method.

BACKGROUND ART

In recent years, high density optical discs typified by DVDs (DigitalVersatile Discs) have been progressively developed and standardized. Toabsorb as many different physical record formats of various types ofmediums as possible and provide a logical structure of an informationstorage unit that has a higher commonality in applications, UDF(Universal Disk Format) was established. A rewritable DVD-RAM(DVD-Random Access Memory) uses a logical format corresponding to theUDF. In addition, the UDF can be applied to a one-time writable CD-R anda rewritable CD-RW.

The UDF is structured with a hierarchical file system. In the UDF, withinformation stored under a root directory, a sub directory and an entityfile are referenced. In addition, with information stored in a subdirectory, another sub directory and an entity file are referenced.Hereinafter, a directory is abbreviated as “Dir.”.

In other words, a record area on a disc is accessed as sectors. A sectoris the minimum unit of storage. On a DVD-RAM, the disc is accessed fromthe inner periphery side to the outer periphery side. From the innermostperiphery side, a lead-in area is formed. The lead-in area is followedby a system area. In the system area, volume information is written. Asthe volume information, VRS (Volume Recognition Sequence), MVDS (MainVolume Descriptor Sequence), LVIS (Logical Volume Integrity Sequence),and AVDP (Anchor Volume Descriptor Pointer) are written.

The location of a record area at which a file entry (hereinafterabbreviated as “FE”) of the root Dir. is recognized by successivelyreferencing the AVDP, the MVDS, and the FSD. An FE is composed ofattribute information for a file or a directory and an allocationdescriptor (hereinafter abbreviated as “AD”). An AD is information of alogical address of a file or a directory and a size (length). An ADrepresents a record area at which entity data of a file is recorded or arecord area at which an entity of a directory is recorded.

At the FE of the root Dir., the AD represents a logical address and alength of an entity of the root Dir. The root Dir. contains at least onefile identifier descriptor (hereinafter abbreviated as “FID”). With anFID, an FE of a sub directory or an FE of a file under the rootdirectory is referenced. With these FEs, the entity of the correspondingsub Dir. and the entity of the file are referenced by respective ADs. Inaddition, an entity of a sub Dir. may contain at least one FID. In otherwords, in the UDF, except for the root Dir., with FIDs and FEs aspointers, the FIDs, FEs, and entities are successively accessed andrecognized. In the UDF, FIDs, FEs, and entities can be written anyrecordable areas.

For example, on the innermost periphery of a disc, the lead-in area isformed. On the outer periphery of the lead-in area, a system area isformed. The entity of the root Dir. is formed for example on the outerperiphery of the system area.

Next, the case that a file is accessed from the root Dir. through a subDir. will be described. Corresponding to the FID of the entity of theroot Dir., an FE of the sub Dir., the FE being at an address physicallyapart from the entity of the root Dir., is referenced. Likewise,corresponding to an AD of an FE of the sub Dir., the entity of the subDir., the entity being at an address apart from the FE of the sub Dir.,is referenced. Likewise, the FID of the entity of the sub Dir. isreferenced. An FE of the file, the FE being at an address apart from theentity of the sub Dir., is referenced. With an AD of the FE of the file,the entity of the file, the entity being at an address apart from the FEof the file, is referenced.

Thus, conventionally, when information of directories and files isdispersed on a disc, it takes a long time to read these information. Tosolve such a problem, it is possible to collectively record pointerinformation such as FIDs and FEs at a predetermined area of a disc.

However, in such a case, if a file is deleted from a disc, since acorresponding FE and so forth are deleted, blank addresses take place.In this case, a file may be written to a blank address. As a result,pointer information that has been collectively written to thepredetermined area may be separated. As a result, it may take a longtime to read information of directories and files.

In addition, while the disc is being used, if any defect takes place inhierarchical structure management information for a file system, themanagement information being composed of pointer information such asFIDs and FEs, the drive apparatus cannot read the managementinformation. In addition, while the disc is being used, if any defecttakes place in an FE of a file, the FE representing a record area(location) of entity data of the file, the drive apparatus cannot readthe FE of the file. In such a case, even if any defect does not takeplace in entity data of moving picture data or audio data, since thedrive apparatus cannot read the management information or the FE of thefile, the drive apparatus cannot access the entity data.

DISCLOSURE OF THE INVENTION

Therefore, a first object of the present invention is to provide arecording method that allows a file to be accessed always at high speedwithout a separation of pointer information and an area for the pointerinformation to be recognized.

A second object of the present invention is to provide a recordingmethod for recording management information as a file to a record mediumso that when a defect takes place in the management information, withreference to the file, the management information can recovered.

A third object of the present invention is to provide a recording methodfor backing up an FE of a file so that when any defect takes place inthe FE of the file, with reference to the backup FE, the FE of the filecan be recovered.

A fourth object of the present invention is to provide a recordingapparatus and a record medium using these recording methods.

The present invention is a recording method for recording data to a discshaped record medium corresponding to a hierarchical file system, themethod comprising the steps of recording management information formanaging a hierarchical structure of the file system to a particulararea of the disc shaped record medium, treating an unused area of theparticular area as a particular file, and recording information withrespect to an initial location and an initial length of the particularfile and information with respect to a current location and a currentlength of the particular file to the particular area.

The present invention is a recording apparatus that records data to adisc shaped record medium corresponding to a hierarchical file system,the apparatus comprising a means for recording management informationfor managing a hierarchical structure of the file system to a particulararea of the disc shaped record medium, a means for treating an unusedarea of the particular area as a particular file, and a means forrecording information with respect to an initial location and an initiallength of the particular file and information with respect to a currentlocation and a current length of the particular file to the particulararea.

The present invention is a disc shaped record medium on which data isrecorded corresponding to a hierarchical file system, managementinformation for managing a hierarchical structure of the file systembeing recorded to a particular area of the disc shaped record medium, anunused area of the particular area being treated as a particular file,information with respect to an initial location and an initial length ofthe particular file and information with respect to a current locationand a current length of the particular file being recorded to theparticular area.

Thus, according to the present invention, when data is recorded to adisc shaped record medium corresponding to a hierarchical file system,management information for managing a hierarchical structure of the filesystem is recorded to a particular area of the disc shaped record mediumand an unused area of the particular area is treated as a particularfile. Thus, an area to which the management information for managing thehierarchical structure of the file system is added is securelyallocated. Consequently, the hierarchical structure of the file systemcan be read at high speed. Thus, the reproduction start time can beremarkably reduced in comparison with the conventional method.

In addition, according to the present invention, since information withrespect to an initial location and an initial length of a particularfile and information with respect to a current location and a currentlength of the particular file are recorded in a particular area, alocation and a length of the particular area can be securely recognized.

The present invention is a recording method for recording data to arecord medium corresponding to a hierarchical file system, the methodcomprising the steps of recording management information for managing ahierarchical structure of the file system to a particular area of therecord medium, treating an unused area of the particular area as aparticular file, copying all the particular area to another area as itis and treating all the copied particular area as one backup file, andif a part of the management information cannot be read, reducing alength of the particular file, creating a blank portion of theparticular area, and recovering the part of the management informationthat cannot be read with data corresponding to the part of the backupfile in the blank portion of the particular area.

The present invention is a recording apparatus that records data to arecord medium corresponding to a hierarchical file system, the apparatuscomprising a means for recording management information for managing ahierarchical structure of the file system to a particular area of therecord medium, a means for treating an unused area of the particulararea as a particular file, a means for copying all the particular areato another area as it is and treating all the copied particular area asone backup file, and a means for reducing a length of the particularfile, creating a blank portion of the particular area, and recovering apart of the management information that cannot be read with datacorresponding to the part of the backup file in the blank portion of theparticular area, if the part of the management information cannot beread.

In the recording method and the recording apparatus, since originalmanagement information can be recovered with a backup file, even if adefect takes place in a part of the management information, entity datarecorded on a record medium can be securely reproduced. In addition,since data to be recovered is placed in a particular area for theoriginal management information, after the recovery, the managementinformation can be collectively placed in the particular area. Thus,after the recovery, the hierarchical structure of the file system can beread at high speed. As a result, the reproduction start time can beremarkably reduced in comparison with the conventional method.

The present invention is a recording method for recording data to arecord medium corresponding to a hierarchical file system, the methodcomprising the steps of recording management information for managing ahierarchical structure of the file system to a particular area of therecord medium, treating an unused area of the particular area as aparticular file, dually recording information that designates a recordlocation of entity data of a file as regular information and backupinformation to the record medium, and reducing a length of theparticular file, creating a blank area of the particular area, andrecording designation information that designates record locations ofthe regular information and the backup information to the blank area ofthe particular area.

The present invention is a recording apparatus that records data to arecord medium corresponding to a hierarchical file system, the apparatuscomprising a means for recording management information for managing ahierarchical structure of the file system to a particular area of therecord medium, a means for treating an unused area of the particulararea as a particular file, a means for dually recording information thatdesignates a record location of entity data of a file as regularinformation and backup information to the record medium, and a means forreducing a length of the particular file, creating a blank area of theparticular area, and recording designation information that designatesrecord locations of the regular information and the backup informationto the blank area of the particular area.

In the recording method and the recording apparatus, since informationthat designates a location of entity data of a file is dually recorded,the security of the information can be improved.

In addition, according to the present invention, when regularinformation cannot be read due to an occurrence of a defect, usingbackup information, the regular information can be newly recovered tothe record medium. Thus, even if the regular information cannot be read,entity data of a file can be read. In addition, whenever regularinformation cannot be read, it is recovered with backup information.Thus, unless both the regular information and the backup informationcannot be read, entity data of a file can be read.

According to the present invention, the recording method furthercomprises the steps of copying all the particular area to another areaas it is and treating all the copied particular area as one backup file,and if a part of the management information cannot be read, reducing alength of the particular file, creating a blank portion of theparticular area and recovering the part of the management informationthat cannot be read with data corresponding to the part of the backupfile in the blank portion of the particular area.

In the recording method, since original management information can berecovered with a backup file, even if a defect takes place in a part ofthe management information, entity data recorded on a record medium canbe securely reproduced. In addition, since data to be recovered isplaced in a particular area for the original management information,after the recovery, the management information can be collectivelyplaced in the particular area. Thus, after the recovery, thehierarchical structure of the file system can be read at high speed. Asa result, the reproduction start time can be remarkably reduced incomparison with the conventional method.

According to the present invention, the recording method furthercomprises the step of recording information with respect to an initiallocation and an initial length of the particular file and informationwith respect to a current location and a current length of theparticular file to the particular area.

In the recording method, since information with respect to an initiallocation and an initial length of the particular file and informationwith respect to a current location and a current length of theparticular file is recorded to the particular area, a location and alength of the particular area can be securely recognized.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram showing the relation between a logicalformat of a disc shaped record medium and the disc shape thereof;

FIG. 2 is a schematic diagram for explaining a method for creating anSMF in an SMA-2 area according to a first embodiment of the presentinvention;

FIG. 3 is a schematic diagram for explaining a method for adding a subdirectory after a format process has been performed;

FIG. 4 is a first part of a schematic diagram for explaining a processfor adding a file under a root directory after a format process has beenperformed according to the first embodiment;

FIG. 5 is a second part of a schematic diagram for explaining a processfor adding a file under a root directory after a format process has beenperformed according to the first embodiment;

FIG. 6 is a schematic diagram for explaining a state that a secondentity of an SMF has run out according to the first embodiment;

FIG. 7 is a schematic diagram for explaining a process for extending thesecond entity of the SMF according to the first embodiment;

FIG. 8 is a first part of a schematic diagram for explaining a methodfor deleting a sub directory that has been added after a format processhad been performed according to the first embodiment;

FIG. 9 is a second part of a schematic diagram for explaining a methodfor deleting a sub directory that has been added after a format processhad been performed according to the first embodiment;

FIG. 10 is a block diagram showing the structure of an example of adrive apparatus;

FIG. 11 is a schematic diagram for explaining the structure of an SMA-2after a format process has been performed according to a secondembodiment;

FIG. 12 is a schematic diagram for explaining a method for adding a subdirectory and a file after a format process has been performed accordingto the second embodiment;

FIG. 13 is a schematic diagram showing states of an SMA-2 area, an SMA-4area, and a backup file in the case that a second entity of an SMF hasbeen extended according to the second embodiment;

FIG. 14 is a schematic diagram for explaining a process for recoveringan FE of a sub Dir. in that case that a defect has taken place in the FEof the sub Dir. according to the second embodiment;

FIG. 15 is a schematic diagram for explaining a process for recoveringan entity of a sub Dir. in the case that a defect has taken place in theentity of the Sub Dir. according to the second embodiment;

FIG. 16 is a schematic diagram for explaining the structures of an SMA-2area and an SMA-3 area before a backup of a file entry of a child fileis created according to a third embodiment;

FIG. 17 is a schematic diagram showing a file identifier descriptoraccording to the third embodiment;

FIG. 18 is a schematic diagram for explaining a creation of a backup ofa file entry of a child file according to the third embodiment;

FIG. 19 is a schematic diagram showing a format of an implementation useaccording to the third embodiment; and

FIG. 20 is a schematic diagram for explaining a process for recovering afile entry of a child file in which a defect has taken place accordingto the third embodiment.

BEST MODES FOR CARRYING OUT THE INVENTION

Next, with reference to the accompanying drawings, embodiments of thepresent invention will be described. In each drawing, similar structureis denoted by similar reference numeral.

First Embodiment

According to a first embodiment of the present invention, managementinformation is collectively recorded in a predetermined area. Thus, evenif data is added or deleted, a drive apparatus can recognize a filestructure at high speed.

FIG. 1 is a schematic diagram showing the relation between a logicalformat of a disc shaped record medium and the disc shape thereof.

FIG. 2 is a schematic diagram for explaining a method for creating anSMF in an SMA-2 area according to the first embodiment.

In FIG. 1, a logical format of a disc shaped record medium 10 is basedon UDF (Universal Disk Format). On the disc shaped record medium 10, alead-in area 11 is formed on the innermost periphery thereof. On theouter periphery of the lead-in area 11, logical sector numbers(hereinafter abbreviated as LSNs) are assigned. A volume informationarea 12, an SMA (Space Management Area)-1 area 15, an SMA-2 area 16, anSMA-3 area 17, and a volume information area 13 are successively formed.On the outermost periphery, a lead-out area 14 is formed. The logicalsector number of the beginning sector of the volume information area 12is “0” as a reference sector. On the other hand, logical block numbers(hereinafter abbreviated as “LBNs”) are assigned to the SMA-1 area 15 tothe SMA-3 area 17 in such a manner that the logical block number of thebeginning sector of the SMA-1 area is “0” as a reference block.

Corresponding to the prescription of the UDF, the VRS, the MVDS, and theLVIS are written in the volume information area 12. At LSN 256 of thevolume information area 12, the AVDP is placed. In addition, the AVDP iswritten to a sector having the last logical sector number and a sectorhaving (last logical sector number—256). The content of the MVDS iswritten as an RVDS (Reserve Volume Descriptor Sequence) twice in thevolume information area 13 on the inner periphery of the lead-out area14.

A partition area is formed between sectors having logical sector number272 and (last logical sector number—272). The SMA-1 area 15 to the SMA-3area 17 are formed in the partition area. Corresponding to theprescription of the UDF, the SMA-1 area 15 formed on the innermostperiphery side of the partition area is composed of an FSDS (File SetDescriptor Sequence) and an SBD (Space Bitmap Descriptor). The FSDS iscomposed of an FSD (File Set Descriptor) and a TD (TerminatingDescriptor). The SBD contains information that represents the entireblank areas of the disc shaped record medium 10. A blank area of eachsector is represented with a flag. The FSD represents a logical addressand a length of an FE (File Entry) against the root Dir. in thehierarchical structure of the file system.

In FIGS. 1 and 2, the SMA-2 area 16 is an area in which the FE of theroot Dir., the entity of the root Dir., an FE of an SMF (SpaceManagement File), and an entity of the SMF are placed. As will bedescribed later, when a required amount of the entity of the SMF isreduced, an FE of a sub Dir. and an entity of the sub Dir. that containsan FID that represents a file are placed in the SMA-2 area 16. In otherwords, the FID and the FE of the directory are collectively recorded inthe SMA-2 area 16.

The SMF is composed of two entities. The two entities are represented byAD-0 and AD-1 in the FE of the SMF. The first entity of the SMF is anarea that describes information of a location (logical address) and alength of an area that has been initially allocated as the second entityof the SMF. In FIG. 2, the first entity of the SMF is an area denoted bythe AD-0. As will be described later, the second entity of the SMF is anarea allocated for an FID and an FE of a directory created while data isrecorded on the disc shaped record medium 10 after a format process hasbeen performed. In FIG. 2, the second entity of the SMF is an arearepresented by the AD-1.

Thus, since the SMF is divided into two entities and information of aninitial location and an initial length of the second entity aredescribed in the first entity, regardless of a location at which the FEof the SMF has been recorded and a location at which the FE of the rootDir. has been recorded, the SMA-2 area 16 can be defined. In addition,as will be described later, with the two entities of the SMA, after asub Dir. and a file under the root directory have been deleted, thedrive apparatus can flexibly operate.

In the SMF, when a format process is performed, an unused area of theSMA-2 area 16 is allocated as a file that has a predetermined capacityand to which a predetermined attribute has been added. Since an unusedarea of the SMA-2 area 16 is treated as a file, with the forgoing SBD,the unused area can be prevented from being recognized as a blank area.

The FE of the root Dir., the entity of the root Dir., and the FE of theSMF can be placed at any sectors of the SMA-2 area 16. However, toaccess them at high speed, as shown in FIG. 1, it is preferred tosuccessively record them. Of course, one object of the present inventionof which the drive apparatus recognizes at high speed a sector forinformation recorded on the disc shaped record medium 10 can beaccomplished with the SMF.

As was described in the foregoing Related Art section, an FE representsa location and a length of an entity of a file or a directory. An AD ofthe FE describes these information. An FID represents a location and alength of an FE with a name of a file or a directory and an ICB(Information Control Block) of the FID.

The SMA-3 area 17 is an area for an FE of a file and data of the file.In the SMA-3 area 17, it is preferred to successively place an FE of afile and data of the file corresponding thereto at adjacent addresses.When a file is added, it is preferred to successively place an FE of thefile to be added and an existing file at adjacent addresses. Inaddition, it is preferred to successively place data of the file and theFE thereof at adjacent addresses. When an FE of a file and data thereofare successively placed at adjacent addresses, the file can be accessedat high speed.

Next, an example of a method for formatting the disc shaped recordmedium 10 will be described. It is assumed that the lead-in area 11 andthe lead-out area 14 have been created in a press process of afabrication process of the disc shaped record medium 10. In other words,it is assumed that before a format process has been performed, thelead-in area 11 and the lead-out area 14 have been formed. The formatprocess is performed from the inner periphery side to the outerperiphery side of the disc shaped record medium 10.

When the format process is started, the AVDP is written to a pluralityof predetermined addresses. The forgoing VRS, MVDS, and LVIS are writtenfrom the outer periphery of the lead-in area 11.

Next, a partition is created. In the partition, the SMA-1 area 15 iscreated. The FSD is written to the SMA-1 area 15. The location of theroot Dir. is decided. Next, the SBD is created. At that point, the areaof the SBD is treated as a used area. As a result, an area of the SMF isallocated.

After the SBD and the SMA-1 area 15 have been created, the SMA-2 area 16is created from the outer periphery of the SMA-1 area 15.

When the SMA-1 area 15 is created, corresponding to the FSD written tothe SMA-1 area 15, a sector for an FE of a root Dir. and a sector for anentity of the root Dir. are successively allocated at predeterminedadjacent addresses. The FE of the root Dir. and the entity of the rootDir. are written to these addresses.

The entity of the root Dir. is composed of an FID of a parent Dir. andan FID of an SMF. The FID of the SMF designates a location of the FE ofthe SMF.

At that point, an attribute of the SMF is designated in the FID. Thedesignated attribute of the SMF prevents another apparatus or an OS(Operating System) from deleting, rewriting, or moving the SMF. Forexample, “hidden file attribute” is designated as an attribute of theSMF. The “hidden file attribute” is an attribute that prevents a filetherewith from being browsed in a normal manner.

Next, the FE of the SMF is created. When a format process is performed,the FE of the SMF is composed of the AD-0 that designates an address anda length of a file of a first entity and the AD-1 that designates anaddress and a length of a file of a second entity. Thus, with the FEdesignated, these files are created. The files can be used as dummyfiles. In the FE of the SMF, “read only file attribute” and “system fileattribute” are designated.

The “read only file attribute” is an attribute that represents that afile therewith is a read only file and that the system prohibits thefile therewith from being changed or deleted. The “system fileattribute” is an attribute that represents that a file therewith is afile required by the system. When all these three attributes aredesignated to the SMF, unless it is intentionally operated, it cannot bedeleted, rewritten, or moved. These attributes can be canceled by aknown method.

Thereafter, a first entity of the SMF is created in a sector adjacent tothe sector for the entity of the root Dir. An initial location and aninitial length of the second entity of the SMF are described in thefirst entity of the SMF. In other words, the location and the length ofthe second entity of the SMF that has been allocated in the formatprocess are described in the first entity of the SMF. This format isdescribed as AD corresponding to the UDF. In the specification, a pseudoAD is denoted by [AD]. FIG. 2 shows [AD-SMA2]. As will be describedlater, there is a possibility of which the second entity of the SMF isextended so that there are a plurality of [AD]. To represent the numberof [AD], corresponding to the prescription of the UDF, an AED(Allocation Extended Descriptor) is used. In the specification, thepseudo AED is denoted by [AED].

In such a manner, since the SMF is placed in the SMA-2 area 16, a blankarea of the SMA-2 area 16 can be allocated by the SMF. After a formatprocess is performed, when an FE of a sub Dic. and an entity thereof arewritten, the area of the second entity of the SMF is reduced. The FE ofthe sub Dir. and the entity thereof are created in the SMA-2 area 16.

In such a manner, the SMA-2 area 16 is created. On the outer peripheryof the SMA-2 area 16, the SMA-3 area 17 is formed. No process isperformed for the SMA-3 area 17. In other words, the SMA-3 area 17 is anunused area. After a format process is performed, data of a file isrecorded in the SMA-3 area 17. The RVDS is created skipping the area forthe SMA-3 area 17. As was described above, information of the MVDS thathas been created is written twice. After the RVDS has been created, theformat process of the disc shaped record medium 10 is completed.

Next, a method for adding a sub Dir. after a format process is performedwill be described.

FIG. 3 is a schematic diagram for explaining a method for adding a subdirectory after a format process is performed according to the firstembodiment.

The case that a sub Dir. (new Dir.) is added in the state shown in FIG.2 will be described.

First of all, an FID that represents a new Dir. is added to an entity ofa root Dir. At that point, when a sector for the entity of the root Dir.has a blank area, as shown in FIG. 3, the FID is added to the sector. Incontrast, when the sector does not have a blank space (not shown), afterthe size of the area of a second entity of an SMF is reduced, the FID ofthe new Dir. is added to the resultant blank area.

Next, to add an FE of the new Dir., the length of the area of the secondentity of the SMF is reduced. The FE of the new Dir. is added to theresultant blank area.

Next, to add an entity of the new Dir. (an FID of a parent Dir. in FIG.3), the length of the second entity of the SMF is further reduced. Theentity of the new Dir. is added to the resultant blank area.

Next, to reflect the change of the length of the second entity of theSMF, information of an AD-1 of the FE of the SMF is updated.

As a result, as shown in FIG. 3, the sub Dir. has been added to theSMA-2 area 16. In addition, information with respect to the added subDir. and information with respect to the directory that has beenrecorded are collectively recorded in the SMA-2 area 16.

Next, a process for adding a file to a root Dir. will be described.

FIG. 4 is a first part of a schematic diagram for explaining a processfor adding a file under a root directory after a format process has beenperformed according to the first embodiment of the present invention.

FIG. 5 is a second part of a schematic diagram for explaining a processfor adding a file under a root directory after a format process has beenperformed according to the first embodiment of the present invention.

Next, the case that a file (new Dir.) is added to a root Dir. in thestate shown in FIG. 2 will be described.

First of all, an FID that represents a new file is added to an entity ofa root Dir. At that point, when a sector for the entity of the root Dir.has a blank space, as shown in FIG. 4, the FID is added to the sector.

In contrast, when the sector does not have a blank space, as shown inFIG. 5, the length of an area for a second entity of an SMF is reduced.The FID of the new file is added to the resultant blank area. In thiscase, since the length of the second entity of the SMF has been changed,information of an AD-1 of the FE of the SMF is updated.

Next, an FE of the new file is added to an SMA-3 area 17. Next, anentity of the new file (data of a parent file in FIGS. 4 and 5) is addedto the SMA-3 area 17. In such a manner, the FE of the file and theentity thereof are placed in the SMA-3 area 17.

As a result, as shown in FIG. 4 or 5, the new file is added to the rootDir. In addition, information with respect to the added new file andinformation with respect to an existing directory that has been recordedare collectively recorded in the SMA-2 area 16.

When a plurality of files are recorded, to allow them to be successivelyaccessed at high speed, it is preferred to successively place an FE ofone file, an entity thereof, an FE of another file, an entity thereof,and so forth.

An FE of a file to be added (the file is referred to as file A) iscreated at an address represented by an FID added to an entity of theroot Dir. An entity of the file A is written to an address adjacent tothe FE of the address A. When file B, file C, . . . , and so forth aresuccessive written, an entity of the file B is created at an addressadjacent to the address of the entity of the file A. An entity of thefile B is written at an address adjacent to the address of the FE of thefile B. This applies to the file C. In other words, an FE of the file Cis written at an address adjacent to the address of the entity of thefile B. An entity of the file C is written at an address adjacent to theaddress of the FE of the file C.

When many sub Dirs. and new files are added to a root Dir. placed in anSMA-2 area 16, an FID of an entity of the root Dir., FEs of sub Dirs.,and FIDs of new files of entities of the sub Dirs. are added. As aresult, it can be considered that the SMA-2 area 16 becomes full withthe added FEs and FIDs. This state is shown in FIG. 6.

FIG. 6 is a schematic diagram for explaining the state that the secondentity of the SMF has run out according to the first embodiment.

In FIG. 6, since the second entity of the SMF has run out, an AD-1 thatrepresents the second entity of the SMF has been lost. However, sincethe first entity of the SMF describes the information with respect tothe second entity of the SMF, the drive apparatus can recognize thelocation and the length of the SMA-2 area 16. As a result, the driveapparatus can recognize the relation between directories and files athigh speed.

In this case, when the SMA-3 area 17 has a blank space, the SMA-3 area17 is divided into a plurality of SMA areas. As a result, an SMA-4 areathat is an extension area of the SMA-2 area 16 and an SMA-5 areaequivalent to the SMA-3 area in which data is recorded are newly createdoutside the location of a file in the SMA-3 area 17. This state is shownin FIG. 7.

FIG. 7 is a schematic diagram for explaining a process for extending thesecond entity of the SMF according to the first embodiment.

In FIG. 7, since the SMA-4 area is allocated, information with respectto the initial location and the length of the SMA-4 area is added in theAD format as [AD-SMA4] to an entity represented by the AD-0 of the SMF.As the table is added, [AED] is updated. A location and a length thatrepresent the newly allocated SMA-4 area are added as an AD-2 to the FEof the SMF.

When a sub Dir. or a file is added to the root Dir., the forgoingoperation described with reference to FIGS. 3 to 5 is performed for thesecond entity of the SMF represented by the AD-2.

Next, the case that a sub Dir. is deleted will be described.

FIG. 8 is a first part of a schematic diagram for explaining a methodfor deleting a sub directory that has been added after a format processhad been performed according to the first embodiment.

FIG. 9 is a second part of a schematic diagram for explaining a methodfor deleting a sub directory that has been added after a format processhad been performed according to the first embodiment.

FIG. 8 shows the state of an SMA-2 area 16 before a sub Dir. is deleted.FIG. 9 shows the state of the SMA-2 area 16 after the sub Dir. has beendeleted.

In FIG. 8, as was described with reference to FIG. 3, after a formatprocess had been performed, a plurality of sub Dirs. have been added,FIDs of added sub Dirs. (for example, an FID of new Dir. 1, an FID ofnew Dir. 2, an FID of new Dir. 3, . . . , and so forth) are added to theentity of the root Dir. Correspondingly, in a blank area of which thesecond entity of the SMF is reduced, FEs and entities of the added subDirs. (for example, an FE and an entity of the new Dir. 1, an FE and anentity of the new Dir. 2, an FE and an entity of the new Dir. 3, and soforth are added).

Next, the case that a sub Dir. is deleted in such a state will bedescribed.

First of all, the drive apparatus references a first entity of an SMFrepresented by an AD-0 of an FE of the SMF and recognizes an initialrange of a second entity with a location and a length represented by[AD].

Next, the drive apparatus deletes an FID, an FE, and an entity of a subDir. to be deleted. To reflect their deletion, an entity in which theFID to be deleted is described is updated.

Next, the drive apparatus determines whether or not the FE and theentity of the sub Dir. that has been deleted are in their initialranges.

When the FE and the entity of the sub Dir. that have been deleted are intheir initial ranges, since the areas for the FE and the entity of thesub Dir. that has been deleted becomes unused areas, the drive apparatusadds an AD that represents the unused areas to the FE of the SMF.

For example, in the state shown in FIG. 8, when a sub Dir. to be deletedis the new Dir. 2, as shown in FIG. 9, the FID of the new Dir. 2 isdeleted from the entity of the root Dir. An AD that represents sectorsfor the FE and entity of the new Dir. 2 is added as AD-12 to the FE ofthe SMF.

Since information with respect to an initial location and a length of asecond entity of an SMF is described in a first entity of the SMF, itcan be determined whether or not a sub Dir. to be deleted is in theinitial range of the second entity of the SMF. When the sub Dir. to bedeleted is in the initial range of the second entity of the SMF, byadding the sectors for the FE and the entity of the sub Dir. that hasbeen deleted to the FE of the SMF, the sectors can be treated as thesecond entity of the SMF. Thus, since the sectors are treated as theSMF, although they are recognized as a part of a file, when a new subDir. is added, the sectors can be used. Thus, information with respectto directories can be collected in one area.

In the forgoing example, the case that a sub Dir. is deleted wasexplained. However, when a file or an FID is deleted, if a blank sectortakes place, it is determined whether or not the blank sector is in aninitial range of the second entity of the SMF. Corresponding to thedetermined result, the forgoing process is performed.

Next, a drive apparatus according to the present invention will bedescribed.

FIG. 10 is a schematic diagram showing the structure of an example ofthe drive apparatus.

In this example, the foregoing disc shaped record medium 10 is a recordmedium whose record layer is made of a phase change metal material.Using a phase change technology of which the temperature applied to therecord layer is controlled with the laser output that is adjusted andthereby the crystal/non-crystal states of the record layer are changed,the drive apparatus 50 records data to the disc shaped record medium 10.

In FIG. 10, the drive apparatus 50 comprises a spindle motor 51, anoptical pickup 52, a laser driver 53, a record equalizer 54, a buffermemory 55, an encoder/decoder circuit (hereinafter abbreviated as“ENC/DC circuit”) 56, a thread mechanism 57, an RF signal processingcircuit 58, an address extraction 59, a drive controlling microcomputer60, an interface (hereinafter abbreviated as “I/F”) 61, a servo circuit62, and a memory 63.

The spindle motor 51 rotates and drives the disc shaped record medium 10that has been chucked. The rotation speed of the spindle motor 51 isservo-controlled by the servo circuit 62.

Data is recorded or reproduced to/from the disc shaped record medium 10through the optical pickup 52. The optical pickup 52 is thread-traveledin the radius direction of the disc shaped record medium 10 by thethread mechanism 57.

Data that is input from an external digital apparatus 71 is supplied tothe drive apparatus 50 through the I/F 61, for example, SCSI (SmallComputer System Interface). The digital apparatus 71 inputs and outputsa digital signal. As long as the digital apparatus 71 inputs and outputsa digital signal and complies with the interface, any digital apparatus71 can be used. The digital apparatus 71 is for example a personalcomputer, a camera integrated portable digital video camcorder, adigital still camera, or a cellular phone. The digital apparatus 71 maybe built in one of those apparatuses.

The ENC/DEC circuit 56 and the drive controlling microcomputer areconnected to the I/F 61. The buffer memory 55, the record equalizer 54,the RF signal processing circuit 58, the servo circuit 62, and the drivecontrolling microcomputer 60 are connected to the ENC/DEC circuit 56.

The memory 55 is a buffer memory that stores write data or read data.Write data is supplied from the digital apparatus 71 to the ENC/DECcircuit 56 through the I/F 61. In the recording mode, the ENC/DECcircuit 56 generates data in the forgoing format and encodes datacorresponding to the format. In the reproducing mode, the ENC/DECcircuit 56 performs a decoding process and outputs the decoded data tothe digital apparatus 71 through the I/F 61.

An address is added as a sub code by the ENC/DEC circuit 56. Inaddition, an address is added to a header of data.

Data that is output from the ENC/DEC circuit 56 is supplied to the laserdriver 53 through the record equalizer 54. The laser driver 53 generatesa drive waveform having a predetermined level necessary for recordingdata to the disc shaped record medium 10. An output signal of the laserdriver 53 is supplied to a laser device of the optical pickup 52. Thelaser device radiates laser light having an intensity corresponding tothe output signal to the disc shaped record medium 10. As a result, thedata is recorded on the disc shaped record medium 10. The laser driver53 properly controls the intensity of the laser light under the controlof an APC (Automatic Power Control) of the RF signal processing circuit58.

In contrast, a signal generated by the optical pickup 52 correspondingto light reflected from the disc shaped record medium 10 is supplied tothe RF signal processing circuit 58. The address extracting circuit 59extracts address information corresponding to the signal supplied fromthe RF signal processing circuit 58. The extracted address informationis supplied to the drive controlling microcomputer 60.

A matrix amplifier of the RF signal processing circuit 58 calculates adetection signal of a photo detector of the optical pickup 52. As aresult, the RF signal processing circuit 58 generates a tracking errorsignal TE and a focus error signal FE. The tracking error signal TE andthe focus error signal FE are supplied to the servo circuit 62.

The drive controlling microcomputer 60 controls a seek operation with anaddress and controls a laser power with a control signal. The drivecontrolling microcomputer 60 comprises a CPU (Central Processing Unit),a RAM (Random Access Memory), and a ROM (Read Only Memory). The drivecontrolling microcomputer 60 controls the entire drive apparatus such asthe I/F 61, the ENC/DEC circuit 56, the RF signal processing circuit 58,and the servo circuit 62. Thus, the drive controlling microcomputer 60performs the forgoing various processes when a sub Dir. is added ordeleted and a file is added or deleted. The memory 63 may be connectedto the drive controlling microcomputer 60.

In addition, an RF signal that is reproduced from the disc shaped recordmedium 10 is supplied to the ENC/DEC circuit 56. The ENC/DEC circuit 56performs a decoding process corresponding to a predetermined format. Inother words, the ENC/DEC circuit 56 demodulates data that has beenmodulated in the recording mode and decodes an error correction code(namely, corrects an error). The ENC/DEC circuit 56 stores thereproduced data to the buffer memory 55. When the buffer memory 55receives a read command from the digital apparatus 71, the read data istransferred to the digital apparatus through the I/F 61.

The frame synchronous signal, the tracking error signal TE, and thefocus error signal FE that are output from the RF signal processingcircuit 58, and the address information that is output from the addressextracting circuit 59 are supplied to the servo circuit 62. The servocircuit 62 performs a tracking servo and a focus servo for the opticalpickup 52, a spindle servo for the spindle motor 51, and a thread servofor the thread mechanism 57.

Second Embodiment

According to a second embodiment of the present invention, even if adefect takes place in management information for managing thehierarchical structure of a file system, the management information canbe recovered and read at high speed.

FIG. 11 is a schematic diagram for explaining the structure of an SMA-2after a format process has been performed according to the secondembodiment. FIG. 2A shows an SMA-2 area, whereas FIG. 2B shows an SMA-3area, in particular, an entity of an BOS.

In FIGS. 1 and 11, a logical format of a disc shaped record mediumaccording to the second embodiment is the same as the logical formataccording to the first embodiment except that an SMA-2 area 16 has an FEof a BOS (Back-up Of Space management file) and an SMA-3 area 17 has anentity of the BOS. Next, only the difference between the logical formatof the second embodiment and the logical format of the first embodimentwill be described.

The SMA-3 area 17 is an area that contains an FE of a file and datathereof. The SMA-3 area 17 also contains an entity of the BOS (data ofthe BOS). The entity of the BOS is a file that backs up managementinformation that is collectively recorded in the SMA-2 area 16. As shownin FIG. 11B, the entity of the BOS is a complete copy of the SMA-2 areathat is obtained by referencing an entity of an AD-0 of an SMF. The FEof the BOS represents a location and a length of the entity of the BOS.As shown in FIG. 11A, the FE of the BOS is recorded in the SMA-2 area16. As shown in FIG. 11B, the FE of the BOS is backed up in the entityof the BOS.

Next, an example of a method for formatting the disc shaped recordmedium 10 according to the second embodiment will be described.

When a format process is started, an AVDP is written to a plurality ofaddresses. The forgoing VRS, MVDS, and LVIS are written from the outerperiphery of a lead-in area 11.

Next, a partition is created. In the partition, an SMA-1 area 15 iscreated. An FSD is written. The location of a root Dir. is decided.Next, an SBD is created. At that point, an area for an SMF is treated asa used area with the SBD. As a result, the area for the SMF isallocated.

After the SBD is created and then the SMA-1 area 15 is created, an SMA-2area 16 is created from the outer periphery of the SMA-1 area 15.

When the SMA-2 area 16 is created, corresponding to the FSD written tothe SMA-1 area 15, a sector for an FE of a root Dir. and a sector for anentity of the root Dir. are successively allocated at predeterminedaddresses. The FE and the entity of the root Dir. are written to thesesectors.

In the format process, the entity of the root Dir. is composed of an FIDof a parent Dir., an FID of an SFM, and an FID of a BOS. The FID of theBOS designates the location of an FE of the BOS.

At that point, attributes of the SMF and BOS are designated in the FIDsthereof. The designated attributes of the SMF and BOS prevent anotherapparatus and the OS (Operating System) from deleting, rewriting, andmoving the SMF and the BOS. For example, “hidden file attribute” isdesignated as an attribute of each of the SMF and BOS.

Next, the FE of the BOS is created. An AD that designates a location anda length of an entity of the BOS are placed in the FE of the BOS. Thelength of the entity of the BOS is a length for which information of theSMA-2 area 16 can be completely copied. Next, an FE of the SMF iscreated.

By designating the FE, the file is created. Thus, by creating the FE ofthe BOS and the FE of the SMF, the area for the entity of the SMF andthe area for the entity of the BOS can be allocated.

In addition, both “read only file attribute” and “system file attribute”are designated to the FE of the BOS and the FE of the SMF. When thesethree attributes are designated to the BOS and the SMF, unless anintentional operation is performed, the BOS and the SMF can be preventedfrom being deleted, rewritten, and moved.

Next, a first entity of the SMF is created in a sector adjacent to thesector for the entity of the root Dir. An initial location and aninitial length of a second entity of the SMF are described in the firstentity of the SMF.

In such a manner, when the SMF is placed in the SMA-2 area 16, a blankarea of the SMA-2 area 16 can be allocated by the SMF. After the formatprocess is performed, when an FE of a sub Dir. and an entity thereof arewritten, the area for the second entity of the SMF is reduced. As aresult, the FE of the sub Dir. and the entity thereof are created in theSMA-2 area 16.

In such a manner, the SMA-2 area 16 is created. On the outer peripheryof the SMA-2 area 16, an SMA-3 area 17 is placed. In a part of the SMA-3area 17, the entity of the BOS is created. The entity of the BOS is afile of management information for managing the hierarchical structureof the file system. The file is recorded in the SMA-2 area 16. When theformat process is performed, the entity of the BOS is composed of the FEof the root Dir., the entity of the root Dir., the FE of the BOS, the FEof the SMF, and the entity of the SMF. The entity of the root Dir. iscomposed of the FID of the parent Dir., the FID of the SMF, and the FIDof the BOS.

The SMA-3 area 17 excluding the entity of the BOS is an unused area.After the format process is performed, data of a file and so forth arerecorded in the unused area. By skipping the area designated as theSMA-3 area 17, the RVDS is created. As a result, the format process forthe disc shaped record medium 10 is completed.

Next, a method for adding a sub Dir. and a file after a format processhas been performed will be described.

FIG. 12 is a schematic diagram for explaining a method for adding a subdirectory and a file after a format process has been performed accordingto the second embodiment. FIG. 12A shows an SMA-2 area, whereas FIG. 12Bshows an SMA-3 area, in particular, an entity of a BOS.

In the state shown in FIG. 11, the case that sub Dir. 1, sub Dir. X, andso forth are added will be described.

First of all, an FID representing the sub Dir. 1 is added to an entityof a root Dir. At that point, when a sector for the entity of the rootDir. has a blank space, as shown in FIG. 12A, the FID is added to thesector. In contrast, when the sector does not have a blank space (notshown), after a length (size) of an area for a second entity of an SMFis reduced, the FID of the sub Dir. 1 is added to the resultant blankarea.

Next, to add an FE of the sub Dir. 1, the length of the second entity ofthe SMF is reduced.

Next, to add an entity of the sub Dir. 1 (an FID of a parent Dir. and anFID of a child file in FIG. 12), the length of the second entity of theSMF is further reduced.

Next, to reflect the change of the length of the second entity of theSMF, the information of the AD-1 of the FE of the SMF is updated.

Next, to reflect the change of the SMA-2 area 16, an entity of a BOS isrewritten. In other words, the content of the SMA-2 area 16 is read andwritten to the area for the entity of the BOS. The entity of the BOS iscomposed of an FE of the root Dir., an entity of the root Dir., an FE ofthe BOS, an FE of the SMF, an entity designated by an AD-0 of the SMF,an FE of the sub Dir. 1, and an entity of the sub Dir. 1. The entity ofthe root Dir. is composed of an FID of the parent Dir., an FID of theSMF, an FID of the BOS, and an FID of the sub Dir. 1. The entity of thesub Dir. 1 is composed of the FID of the parent Dir. and the FID of thechild file.

After such an operation is performed for each of the sub Dir. 2, subDir. 3, and so forth, the content of the SMA-2 area 16 becomes as shownin FIG. 12A.

In the forgoing process, whenever the content of the SMA-2 area ischanged, the content of the entity of the BOS that backs up the contentof the SMA-2 area is changed. However, the present invention is notlimited to such an example. Instead, the content of the entity of theBOS may be changed when the disc shaped record medium 10 is inserted orremoved into/from the drive apparatus, whenever a predetermined timeperiod elapses, whenever the number of FIDs added to the entity of theroot Dir. exceeds a predetermined value (for example, 3), or when apredetermined command is input by the user.

In the forgoing example, the case that a directory is added wasdescribed. Next, the case that a file is added will be described.

First of all, an FID that represents a new file is added to an entity ofa root Dir. At that point, when a sector for the entity of the root Dir.has a black space, the FID is added to the sector. In contrast, when thesector does not have a blank space, a length of an area for a secondentity of an SMF is reduced. The FID of the new file is added to theresultant blank area. In this case, since the length of the secondentity of the SMF has been changed, information of an AD-1 of an FE ofthe SMF is updated. Next, an FE of the new file is added to an area foran SMA-3 area 17. Next, an entity of the new file is added to the areafor the SMA-3 area 17. In such a manner, the FE and the entity of thefile are placed in the SMA-3 area 17.

As a result of such an operation, the new file is added to the root Dir.In addition, information with respect to the added new file andinformation with respect to a directory that has been recorded arecollectively recorded in the SMA-2 area 16.

When many sub Dirs. and many new files are added to the root Dir. placedin the SMA-2 area 16, an FID of an entity of the root Dir., FEs of subDirs., and FIDs of new files in the entities of the sub Dirs. are added.As a result, it can be considered that the added FEs and FIDs cause theSMA-2 area 16 to become full.

In such a case, when the SMA-3 area 17 has a blank space, it is dividedinto a plurality of SMA areas that are an SMA-4 area as an extensionarea of the SMA-2 area 16 and an SMA-5 area equivalent to the SMA-3 areain which data is recorded. As a result, the SMA-4 area and the SMA-5area are newly created on the outer periphery of the location of a fileof the SMA-3 area 17.

FIG. 13 is a schematic diagram showing states of an SMA-2 area and anSMA-4 area and a state of a backup file in the case that a second entityof an SMF is extended according to the second embodiment. FIG. 13A showsthe state of the SMA-2 area in the case that the second entity of theSMF has run out. FIG. 13B shows the states of the SMA-2 area and theSMA-4 area in the case that the second entity of the SMF has beenextended. FIG. 13C shows the state of the backup file.

In FIG. 13B, since the SMA-4 area is allocated, information with respectto an initial location and an initial length of the SMA-4 area is addedas [AD-SMA4] in AD format to an entity designated by an AD-0 of an SMF.As the table is added, [AED] is updated. A location and a length thatrepresent the newly allocated SMA-4 area are added as AD-2 to an FE ofthe SMF.

When an area for an backup of the content of the SMA-4 area has not beenallocated in the SMA-3 area, an entity of a BOS is extended to an SMA-5area (not shown). An AD that describes a location and a length thatrepresent the extended entity of the BOS is added to an FE of the BOS ofthe SMA-2 area 16.

When a sub Dir. and a file are added to the root Dir., an operationsimilar to that described with reference to FIGS. 11 and 12 is performedfor the second entity of the SMF designated by the AD-2.

When a backup file is created, as shown in FIGS. 13B and 13C, onlymanagement information placed in the SMA-2 area and the SMA-4 area isbaked up. In other words, the entity of the BOS is created byreferencing [AD-SMA2] of the entity of the AD-0 of the SMF, directlycopying the SMA-2 area, referencing [AD-SMA4], and directly copying theSMA-4 area.

Next, a method for recovering an FE of a sub Dir. in managementinformation placed in the SMA-2 area in the case that the FE of the subDir. cannot be read will be described.

FIG. 14 is a schematic diagram for explaining a process for recoveringan FE of a sub Dir. in the case the a defect has taken place in the FEof the sub Dir. according to the second embodiment.

FIG. 14A shows a state that a defect has taken place in sub Dir. X.FIGS. 14B and 14C show a state that an FE of the sub Dir. X has beenrecovered in an SMA-2 area 16 using the FE of the sub Dir. X placed inan entity of a BOS.

In FIG. 14A, an FID of the sub Dir. X under a root Dir. is placed in anentity of the root Dir. The FID of the sub Dir. X designates the FE ofthe sub Dir. X placed in LBNb. The FE of the sub Dir. X designates anentity of the sub Dir. X. The entity of the sub Dir. X is composed of anFID of a parent Dir., an FID of a child file, and so forth.

When the FE of the sub Dir. X cannot be read due to a defect in such acase, an implementation recovers management information using the entityof the BOS.

First of all, the implementation checks the LBNb that represents the FEof the sub Dir. X, LBNx that represents the entity of the BOS, and anentity of an AD-0 of an SMF. The implementation recognizes LBNa thatrepresents the start location of the SMA-2 area 16 by referencing theentity of the AD-0 of the SMF.

Next, using the recognized result, the implementation checks a locationof the FE of the sub Dir. X placed in the entity of the BOS.

The implementation checks the entity of the AD-0 of the SMF becausethere is a possibility of which while the disc shaped record medium isbeing used, an FE of a sub Dir., an entity thereof, and an FID of a filecause the SMA-2 area 16 to be extended.

Thus, in the case shown in FIG. 13C, when the implementation checks thelocation of the FE of the sub Dir. X placed in the entity of the BOS,assuming that LBN of the FE of the sub Dir. X represented by the FID isLBNb, the implementation determines an initial location of the LBNb inthe second entity of the SMF. In other words, the implementationdetermines whether the LBNb is in the SMA-2 area with [AD-SMA2] or inthe SMA-4 area with [AD-SMA4]. As a result, the implementation obtainsan offset value from the LBN a. In other words, when the LBNb is in theSMA-2 area, the offset value is (LBNb−LBNa). When the LBNb is in theSMA-4 area, the offset value is (length of SMA-2 area)+(LBNb−(start LBNof SAM-4 area)). The offset value is denoted by f (LBNb, [entity of AD-0of SMF]). In is case, y=f (x) represents that y is a function of x.

When the SMF is not extended, the location of the FE of the sub Dir. Xis LBNx+(LBNb−LBNa). When offset value=f (LBNb, [entity of AD-0 of SMF])is calculated with the LBNX, the implementation can recognize the FE ofthe sub Dir. X placed in the entity of the BOS.

Next, the implementation reads the FE of the sub Dir. X from the entityof the BOS.

Next, to add the FE of the sub Dir. X that has been read, theimplementation reduces the length of the area for the second entity ofthe SMF, changes the descriptor tag in a predetermined manner, and addsthe FE of the sub Dir. X to the resultant blank area.

Next, to reflect the change of a length of the second entity of the SMF,the implementation updates the information of an AD-1 of an FE of theSMF.

Next, to reflect the change of a location of the FE of the sub Dir. X,the implementation rewrites an FID of the sub Dir. X.

Next, to prohibit a defective sector from being accessed, theimplementation causes the defective sector to be excluded from the SMFthat is managed. In other words, the implementation excludes thedefective sector from an entity of an AD-0 of the SMF, the entitydefining the initial area of the SMF.

Next, to reflect the change of an SMA-2 area 16, the implementationrewrites the entity of the BOS.

In such a manner, when the entity of the BOD as a backup of the FE ofthe sub Dir. X is referenced and the length of the area for the secondentity of the SMF is reduced, the defective FE of the sub Dir. X can berecovered in the management information placed in the SMA-2 area 16.Thus, even if the defective FE of the sub Dir. X is recovered, themanagement information can be collectively placed in the SMA-2 area 16.

Next, a method for recovering an entity of a sub Dir. in managementinformation placed in an SMA-2 area 16 in the case that the entity ofthe sub Dir. 1 cannot be read will be described.

FIG. 15 is a schematic diagram for explaining a process for recoveringan entity of a sub Dir. in the case that a defect has taken place in theentity of the sub Dir. according to the second embodiment.

FIG. 15A shows a state that a defect has taken place in an entity of subDir. X. FIGS. 15B and 15C shows a state that the entity of the sub Dir.X is recovered to an SMA-2 area 16 using the entity of the sub Dir. Xplaced in an entity of a BOS.

In FIG. 15A, an FID of the sub Dir. X under a root Dir. is placed in anentity of the root Dir. The FID of the sub Dir. X designates an FE ofthe sub Dir. X. The FE of the sub Dir. X designates the entity of thesub Dir. X placed in LBNC. The entity of the sub Dir. X is composed ofan FID of a parent Dir., an FID of a child file, and so forth. The FIDof the parent Dir. designates an FE of sub Dir. 1. The FID of the childfile designates an FE of a child file placed in an SMA-3 area 17. The FEof the child file designates entity data o the child file.

In such a case, if the entity of the sub Dir. X cannot be read due to adefect, the drive apparatus recovers management information using anentity of a BOS.

First of all, the implementation checks LBNC that designates the entityof the sub Dir. X, LBNx that designates the entity of the BOS, and anentity of an AD-0 of an SMF.

Next, with the checked result, the implementation calculates an offsetfrom the LBNx and obtains a location of the entity of the sub Dir. Xplaced in the entity of the BOS.

Next, the implementation reads the entity of the sub Dir. X from theentity of the BOS.

Next, to add the entity of the sub Dir. X that has been read, theimplementation reduces a length of an area for a second entity of an SMFand adds the entity of the sub Dir. X to the resultant blank area.

Next, to reflect the change of the length of the second entity of theSMF, the implementation updates information of an AD-1 of an FE of anSMF.

Next, to reflect the change of a location of the entity of the sub Dir.X, the implementation rewrites an FE of the sub Dir. X.

Next, to prohibit the defective sector from being accessed, theimplementation causes the defective sector to be excluded from the SMFthat is managed. As a result, the defective sector is not accessed.Thus, the backup can be securely performed.

Next, to reflect the change of an SMA-2 area 16, the implement rewritesthe entity of the BOS.

When the entity of the BOD is referenced and the length of the secondentity of the SMF is reduced, the defective entity of the Dir. X can berecovered to the management information placed in the SMA-2 area 16.Thus, when the defective entity of the sub Dir. X is recovered, themanagement information is collectively placed in the SMA-2 area 16.

Since the structure of the drive apparatus according to the secondembodiment is the same as that shown in FIG. 10, the description will beomitted.

Third Embodiment

According to a third embodiment, if a defect takes place in informationthat designates a record location of entity data of a file, theinformation can be recovered.

Since a logical format of a disc shaped record medium, a format process,and a method for adding a sub Dir. or a file after a format process hasbeen performed according to the third embodiment are the same as thoseaccording to the second embodiment, their description will be omitted.

First of all, an operation for backing up an FE of a file in the casethat a sub Dir. or a file has been created will be described.

FIG. 16 is a schematic diagram for explaining the structures of an SMA-2area and an SMA-3 area before a backup of a file entry of a child fileis created according to the third embodiment.

FIG. 17 is schematic diagram showing a file identifier descriptoraccording to the third embodiment.

FIG. 18 is a schematic diagram for explaining a method for creating abackup of a file entry of a child file according to the thirdembodiment.

FIG. 19 is a schematic diagram showing a format of an implementation useaccording to the third embodiment.

FIG. 16 is a schematic diagram showing a linear representation of arecord area placed concentrically or spirally on a disc shaped recordmedium 10. FIG. 16A mainly shows an SMA-2 area 16. FIG. 16B mainly showsan SMA-3 area 17.

On the disc shaped record medium 10 shown in FIG. 16, by the operationsaccording to the first embodiment and the second embodiment, a pluralityof sub Dirs. are created under a root Dir. In addition, a sub Dir. and afile are created under another sub Dir. Sub Dir. X of the plurality ofsub Dirs. is created under the root Dir. A child file is created underthe sub Dir. X.

To create a sub Dir. and a file, as shown in FIG. 16A, an FE of the rootDir., an entity of the root Dir., an FE of a BOS, an FE of an SMF, anentity of an AD-0 of the SMF, FEs of plurality of sub Dirs., entities ofthe sub Dirs, and an entity of an AD-1 of the SMF are recorded in anSMA-2 area 16. The entity of the root Dir. is composed of an FID of aparent Dir., an FID of the SMF, an FID of the BOS, and FIDs of sub Dirs.

As shown in FIG. 16B, an SMA-3 area 17 is composed of an entity of theBOS, an FE of a file, entity data of the file, and a blank record area(in which substantially meaningful information has not been recorded).For example, a location of an FE of a child file in the sub Dir. X isstored in an ICB of an FID of the child file in the entity of the subDir. X. A location of entity data of the child file is stored in theAD-0 of the FE of the child file.

As shown in FIG. 17, in the UDF, the FID is composed of Descriptor Tag,File Version Number, File Characteristics, Length Of File Identifier,ICB, Length Of Implementation Use, Implementation Use, File Identifier,and Padding.

Next, the FID will be described in brief; for details, refer to the UDFSpecification. The Descriptor Tag is an identifier that identifies adescriptor. Tag Identifier identifies a type of a descriptor. The FileVersion Number represents a version number of the file. The FileCharacteristics a file attribute that represents a hidden file, anot-hidden file, or a directory. The Length Of File Identifierrepresents the size (length) of a file ID. The ICB contains a logicaladdress and a length of an FE (as was described above). The Length OfImplementation Use represents a lengththe Implementation Use. TheImplementation Use will be described later. The File Identifier is anidentifier of the file. The Padding is placed so that the FID, which hasa variable length, becomes a multiple of four bytes.

As shown in FIG. 18, a BFE (Backed up File Entry) that is a backup of anFE of a child file is created in the SMA-3 area 17. When an FE of aregular child file is created, a spare BFE is created.

In FIG. 18, a BFE is recorded immediately after entity data designatedthereby. Alternatively, a BFE may be recorded in any record area of theSMA-3 area 17.

The content of a BFE is the same as the content of an FE to be backedup. An AD-0 of the BFE contains a logical address and a length of entitydata of a child file to be backed up.

To designate a BFE, the Implementation Use of the FID of the child fileis extended.

As shown in FIG. 19, the Implementation Use is composed of Flag,Identifier, OS Class, OS Identifier, Implementation Use Area, andLogical Block Number of Backup BFE.

The Flag, Identifier, OS Class, OS Identifier, and Implementation UseArea comply with the standard of the UDF. The Logical Block Number OfBackup BFE is an extended portion according to the embodiment.

Next, the Implementation Use will be described in brief; for details,refer to the UDF Specification. The OS Class and the OS Identifier arecooperatively used. The OS Class and the OS Identifier represent anoperating system (OS) on which the implementation (that is the entireapparatus including the drive apparatus) is operating. TheImplementation Use Area is an area that the implementation can freelyuse.

The Logical Block Number of Backup BFE contains a location of a BFE thatbacks up a regular FE. The location of the BFE is represented by alogical block number.

The Implementation Use of the FID is also described in theImplementation Use of an FID of a child file in an entity of an BOS.

The UDF Specification is published on the home page of OSTA (OpticalStorage Technology Association) (http://www.osta.org/html/ostaudf.html).Anyone can download the UDF Specification from the home page.

Next, an operation for recovering an FE of a regular child file placedin an SMA-3 area 17 in the case that the FE of the child file cannot beread will be described.

FIG. 20 is a schematic diagram for explaining a process for recovering afile entry of a child file in which a defect has taken place.

FIG. 20 is a schematic diagram showing a linear representation of arecord area placed concentrically or spirally on a disc shaped recordmedium 10 according to the third embodiment. FIG. 20A mainly shows anSMA-2 area 16. FIG. 20B mainly shows an SMA-3 area 17.

In FIG. 20, an FID of sub Dir. X is placed in an entity of a root Dir.The FID of the sub Dir. X designates an FE of the sub Dir. X. The FE ofthe sub Dir. X designates an entity of the sub Dir. X. The entity of thesub Dir. X is composed of an FID of a parent Dir., an FID of a childfile, and so forth. An ICB of the FID of the child file designates an FEof the child file.

In such a case, when the FE of the child file cannot be read due to adefect, the Implementation references the Implementation Use of the FIDof the child file.

Next, the Implementation checks the Logical Block Number of Backup ofthe Implementation Use and obtains a logical block number of the backupBFE.

Next, the Implementation references the BFE with the logical blocknumber thereof and copies the content of the BFE to a blank record areaof the SMA-3 area 17. As a result, the Implementation recovers the FE ofthe regular child file.

Next, to designate the FE of the recovered child file, theImplementation rewrites the content of the ICB of the FID of the childfile in the SMA-2 area 16.

Next, to reflect the rewritten content of the ICB, the Implementationrewrites the content of the FID of the child file of the entity of theBOS of the SFA 17.

Thus, the FE of the recovered child file is newly linked. With the FIDof the child file, the recovered FE of the child file is referenced. Asa result, entity data of the child file can be read. Even if some defecttakes place in the FID of the child file, with reference to the FID ofthe child file in the entity of the BOS, the FID of the child file isrecovered. In addition, the recovered FID of the child file designatesthe recovered FE of the child file.

In addition, whenever an FE of a regular child file cannot be read, witha backup BFE, the FE of the regular child file is recovered. Thus,unless both the FEs cannot be read, entity data of the file can be read.

When there are a plurality of files, there are also a plurality of BFEs.However, these BFEs may be treated as one file. In this case, an FID ofthe file for the BFEs is created in the entity of the root Dir. An FEthat designates these BFEs is created in the SMA-2 area 16. Since theBFEs are treated as a file, an operating system that does not supportthe BFEs cannot use a backup function for an FE of a file. However, thedisc shaped record medium 10 can be treated as a record medium thatcomplies with the conventional UDF. When a file attribute of a BFE isdesignated, “hidden file attribute” is designated in the FID of the BFE.“Read only file attribute” and “system file attribute” are designated inthe FE of the BFE.

Since the structure of the drive apparatus according to the thirdembodiment is the same as the structure of the drive apparatus shown inFIG. 10, the description will be omitted.

In the forgoing embodiments, format data for the disc shaped recordmedium 10 is created by the ENC/DEC circuit 56. However, the presentinvention is not limited to such an example. The format data can becreated by the drive controlling microcomputer 60. Alternatively, theformat data may be supplied from the digital apparatus 71.

In the forgoing embodiments, the present invention is applied to driveapparatuses such as an optical disc drive apparatus and amagneto-optical disc drive apparatus. However, the present invention isnot limited to such examples. In other words, the present invention canbe applied to a record medium drive apparatus that allows data recordedon a record medium to be managed with predetermined managementinformation, for example, a fixed drive apparatus such as a hard diskdrive apparatus.

As was described above, according to the present invention, names,addresses, lengths, and so forth of Dirs. and files managed on a discshaped record medium are collectively recorded in a predetermined area(SMA-2 area) thereof. Thus, these management information can be read athigh speed.

In addition, according to the present invention, since information of aninitial range of an area (a second entity of an SMF) that storesinformation with respect to a sub Dir. and a file under a root Dir. thatare added after a format process is performed has been recorded on adisc shaped record medium, regardless of locations of an FE of the rootDir. and an FE of the SMF, the SMA-2 area can be designated.

In addition, according to the present invention, a blank area of anSMA-2 area is managed as a file. In addition, after a format process hasbeen performed, when a sub Dir. and a file are added and then they aredeleted, although a blank area takes place, it is managed as a part of afile. Thus, the another OS is prevented from writing the SMA-2 area.

In addition, according to the present invention, since a specialattribute is designated to a file managed as a blank area of the SMA-2area, another OS is prevented from deleting the file managed as theblank area.

Alternatively, according to the present invention, managementinformation for managing the hierarchical structure of the file systemis collectively recorded in a predetermined area as a particular file.In addition, since the management information is copied as a backupfile, even if a defect takes place in a part of the original managementinformation, the backup file can be recovered to a predetermined area ofwhich a particular file is deleted. Thus, after a recovery from adefect, by reading the original management information rather than abackup file, the drive apparatus can recognize the hierarchicalstructure of the file system. In addition, when the drive apparatus isrecovered from a defect, since the management information iscollectively recorded in a predetermined area, the drive apparatus canread the management information at high speed.

In addition, according to the present invention, since information withrespect to an initial location and an initial length of a particularfile and information with respect to a current location and a currentlength of the particular file are recorded in a particular area, thedrive apparatus can securely recognize a location and a length of theparticular area.

In addition, according to the present invention, since a defectivesector in which a defect has taken place is not excluded from aparticular file that is managed, the defective sector can be prohibitedfrom being accessed. Thus, a backup file can be securely created.

In addition, according to the present invention, when an SMA-2 area thathas been allocated in a format process becomes full, by rewriting onlyinformation of a file managed as a blank area of the SMA-2 area, it canbe extended.

Alternatively, according to the present invention, since informationthat designates a location of entity data of a file is dually recorded,the security of the information can be improved.

In addition, according to the present invention, when regularinformation cannot be read due to an occurrence of a defect, usingbackup information, the regular information can be newly recovered tothe record medium. Thus, even if the regular information cannot be read,entity data of a file can be read.

In addition, according to the present invention, whenever regularinformation cannot be read, it is recovered with backup information.Thus, unless both the regular information and the backup informationcannot be read, entity data of a file can be read.

1. A recording method for recording data to a disc shaped record mediumcorresponding to a hierarchical file system, the method comprising thesteps of: recording management information for managing a hierarchicalstructure of the file system to a management information area of thedisc shaped record medium; treating an unused area of the managementinformation area as a particular file; recording information withrespect to an initial location and an initial length of the particularfile and information with respect to a current location and a currentlength of the particular file to the management information area; andwherein when a part of the management information is deleted, themanagement information is updated by adding information to themanagement information area relating to a location and a length of ablank portion of which the part of the management information has beendeleted.
 2. The recording method as set forth in claim 1, furthercomprising the steps of: when the management information is added to themanagement information area, reducing a length of the particular filecorresponding to the management information that is added and creating ablank portion of the management information area; and recording themanagement information that is added in the blank portion of themanagement information area.
 3. The recording method as set forth inclaim 1, further comprising the step of: designating a hidden fileattribute, a system file attribute, and a read only file attribute tothe particular file.
 4. The recording method as set forth in claim 1,further comprising the step of: when the management information arearuns out of an area to which the management information is newly added,designating a new particular file to an unused area of the disc shapedrecord medium, recording information with respect to an initial locationand an initial length of the new particular file and information withrespect to a current location and a current length of the new particularfile to the management information area so as to extend an area of theparticular file.
 5. A recording apparatus that records data to a discshaped record medium corresponding to a hierarchical file system, theapparatus comprising: means for recording management information formanaging a hierarchical structure of the file system to a managementinformation area of the disc shaped record medium; means for treating anunused area of the management information area as a particular file;means for recording information with respect to an initial location andan initial length of the particular file and information with respect toa current location and a current length of the particular file to themanagement information area; and wherein when a part of the managementinformation is deleted, the management information is updated by addinginformation to the management information area relating to a locationand a length of a blank portion of which the part of the managementinformation has been deleted.
 6. A disc shaped record medium having aprogram recorded thereon on which data is recorded corresponding to ahierarchical file system, said program comprising the steps of:recording management information for managing a hierarchical structureof the file system being recorded to a management information area ofthe disc shaped record medium; treating an unused area of the managementinformation area being treated as a particular file; recordinginformation with respect to an initial location and an initial length ofthe particular file and information with respect to a current locationand a current length of the particular file being recorded to themanagement information area; and wherein when a part of the managementinformation is deleted, the management information is updated by addinginformation to the management information area relating to a locationand a length of a blank portion of which the part of the managementinformation has been deleted.